Inhibition of Advanced Glycation End Product Formation by Pu-erh Tea Ameliorates Progression of Experimental Diabetic Nephropathy

Abstract

Accumulation of advanced glycation end products (AGEs) has been implicated in the development of diabetic nephropathy. We investigated the effects of Pu-erh tea on AGE accumulation associated with diabetic nephropathy. Although it did not affect blood glucose levels and insulin sensitivy, Pu-erh tea treatment for 8 weeks attenuated the increases in urinary albumin, serum creatinine, and mesangial matrix in db/db mice. We found that Pu-erh tea prevented diabetes-induced accumulation of AGEs and led to a decreased level of receptor for AGE expression in glomeruli. Both production and clearance of carbonyl compounds, the main precursor of AGE formation, were probably attenuated by Pu-erh tea in vivo independent of glyoxalase I expression. In vitro, HPLC assay demonstrated Pu-erh tea could trap methylglyoxal in a dose-dependent manner. Our study raises the possibility that inhibition of AGE formation by carbonyl trapping is a promising approach to prevent or arrest the progression of diabetic complications.

Pu-Erh Tea Extract Induces the Degradation of FET Family Proteins Involved in the Pathogenesis of Amyotrophic Lateral Sclerosis

“…PTE, green tea extract (GTE), and black tea extract (BTE) were kindly supplied by the China Academy of Pu-Erh Tea Research [21, 22]. These extracts were dissolved in distilled water and adjusted to pH 7.4 with 1 M NaOH.…”

“…A number of in vitro and animal studies have demonstrated that pu-erh tea has antioxidant [19] and antiobesity properties [20]. Pu-erh tea also has strong anticancer protective effects [21] and can ameliorate diabetic nephropathy [22]. Several compounds are produced during the postfermentation of pu-erh tea.…”

Advanced glycation end-products and skin autofluorescence in end-stage renal disease: a review

“…The use of many herbal medicines and experimental drugs has shown a reduction of AGE accumulation [49][50][51][52][53][54][55][56]. Also, many conventional drugs are useful in the reduction of AGE.…”

Edible plants from traditional Chinese medicine is a promising alternative for the management of diabetic nephropathy

“…Besides, alloxan (ALX) is another commonly used chemical agent to generate DN model to study the therapeutic effects of propolis (Orsolic, Sirovina, Koncic, Lackovic, & Gregorovic, 2012). Additional models for TCM edible plants studies are also available, such as db/db mice for Puerh tea, and KK-Ay mice for Averrhoa carambola (Yan et al, 2012;Zheng et al, 2013). The merits and drawbacks of these models are summarized and compared by Breyer in a specific review (Breyer et al, 2005).…”

“…Strikingly, grape seed proanthocyanidins showed a pronounced therapeutic effect on experimental DN through multiple cellular targets (Cheng et al, 2007;Li et al, 2009;Liu, Shen, & Yao, 2006;Mansouri et al, 2011). Furthermore, the formation of AGEs was inhibited in db/ db mice after treatment with Pu-erh tea (Yan et al, 2012). Green tea has been well documented for its protective effects in experimental diabetes, which involve a complex mechanism ( Additionally, soybeans and soy foods also have similar effects (Anderson, Smith, & Washnock, 1999).…”